how to take n digit input which are not space separated

Question

NOTE: Please don't write the solution(i.e. algorithmic logic) for this problem.

Yesterday Chef had a great party and doesn't remember the way he celebreated it. But he found a strange paper in his kitchen containing n digits (lets give them indices from 1 to n and name them a1, a2 ... aN).

Chef remembers that he played such game:

On each step he choose an index x from 1 to n.
For all indices y (y < x) he calculated the difference by = ax - ay.
Then he calculated B1 - sum of all by which are greater than 0 and B2 - sum of all by which are less than 0.
The answer for this step is B1 - B2.

Chef remembers the game, but forgot the answer. Please, help him! Input

The first line contains two integers n, m denoting the number of digits and number of steps. The second line contains n digits (without spaces) a1, a2, ..., an.
Each of next m lines contains single integer x denoting the index for current step.

Output

For each of m steps print single number in a line - answer of the step.

Constraints

1 ≤ n, m ≤ 10^5
0 ≤ ai ≤ 9
1 ≤ x ≤ n

now how do i take n digit input?i mean how do i use scanf code in this.i dont5 know exact value of n so i cant declare those many variables.does it mean that i take a single digit input?

Answer 1

Just get one character at a time:

int num = getc(stdin) - '0';

The subtraction of '0' is to turn a character into a number. Obviously error checking is left as an exercise.

Answer 2

(assuming n digit input is a string, with n characters) Use dynamic memory allocation and a customized scanf formatter:

int n = 0;
char* digits = NULL;
char format[256];

printf("n=");
scanf("%d", &n);
digits = calloc(n + 1, 1); /* for the terminator 0 to be initialized*/

snprintf(format, 256, "%%%ds", n); /* to not to cause an overflow */

if(NULL == digits)
{
    printf("Not enough memory");
    exit(1);
}
scanf(format, digits);
printf("%s", digits);

// DO your algorithm here

free(digits);

Answer 3

@user3424954 read the problem statement again it is clearly mention first line inputs n which is the length of the numeral string. You can try using *scanf("%s",array_name);*